A Japanese scientific research team has made a breakthrough discovery that could lead to advances in treatments for cancer patients worldwide.
The team, led by Hiroshi Kawamoto, was successful in reprogramming T lymphocytes, with the ability to kill a certain type of cancer, into induced pluripotent stem (iPS) cells. These fast-growing cells are non-specific, or capable of becoming a number of different types of cells. The iPS cells then generated active cancer-specific cells, or “killer” T lymphocytes, that produce an anti-tumor compound.
Reprogramming Mature Cells into Stem Cells
The research team presented its findings in the journal Cell Stem Cell. Said Dr. Kawamoto, “We have succeeded in the expansion of antigen-specific T cells by making iPS cells and differentiating them back into functional T cells.”
In previous experiments, the very short life span of T lymphocytes rendered them inefficient at killing cancer cells. The scientists’ discovery circumvents this limitation. By exposing mature T lymphocytes specific for a certain skin cancer to a group of compounds called “Yamanaka factors,” the team was able to reprogram them into iPS cells, which were then induced into killer T lymphocytes.
The resulting killer T lymphocytes were shown to be active, and to retain the same specificity for the skin cancer as the original lymphocytes. The reprogrammed cells’ ability to express the cancer-specific receptor on their surfaces was maintained throughout the process.
An Immune System Boost for Cancer Patients?
While the Japanese research team has accomplished a first-in-the-world discovery, there are still many more tests and experiments to conduct. It is hoped that the killer T lymphocytes can be injected into cancer patients to super-charge their immune systems and kill cancerous tumors. However, they must first be deemed safe. T cells occur naturally in the human body, but in small numbers. Whether the cells can be made patient-specific (to avoid rejection by the immune system) is an unknown. In addition, the cells have not been tested to determine whether they will attack only cancerous cells, and not destroy healthy cells.
Researchers will next work on this aspect. “The next step will be to test whether these T cells can selectively kill tumor cells but not other cells in the body,” said Dr. Kawamoto.
Promising Findings in the Fight Against Cancer
The Japanese team has expanded the body of knowledge of cell-based therapy, and successfully proven that these cancer-killing cells can be produced in the lab. But experts in the field say it must still be proven that these cells can make a difference in cancer patients. The team’s findings are promising, and provide hope that additional research could lead to new treatments in the future, not only for cancer, but for infectious diseases, such as HIV, as well.